Plasminogen activator inhibitor-1 (PAI-1) is a major regulatory component of the plasminogen-plasmin system. PAI-1 is the principal physiologic inhibitor of both tissue type plasminogen activator (tPA) and urokinase type plasminogen activator (uPA). Elevated plasma levels of PAI-1 have been associated with thrombotic events as indicated by animal experiments (Krishnamurti, Blood, 69, 798 (1987); Reilly, Arteriosclerosis and Thrombosis, 11, 1276 (1991); Carmeliet, Journal of Clinical Investigation, 92, 2756 (1993)) and clinical studies (Rocha, Fibrinolysis, 8, 294, 1994; Aznar, Haemostasis 24, 243 (1994)). Antibody neutralization of PAI-1 activity resulted in promotion of endogenous thrombolysis and reperfusion (Biemond, Circulation, 91, 1175 (1995); Levi, Circulation 85, 305, (1992)). Elevated levels of PAI-1 have also been implicated in diseases of women such as polycystic ovary syndrome (Nordt, Journal of clinical Endocrinology and Metabolism, 85, 4, 1563 (2000)) and bone loss induced by estrogen deficiency (Daci, Journal of Bone and Mineral Research, 15, 8, 1510 (2000)). Accordingly, agents that inhibit PAI-1 would be of utility in treating conditions originating from fibrinolytic disorder such as deep vein thrombosis, coronary heart disease, pulmonary fibrosis, Alzheimer's disease, polycystic ovary syndrome, etc.
WO 99/43654 and WO 99/43651 disclose indole derivatives of the following formula as inhibitors of phospholipase enzymes useful in preventing inflammatory conditions.

U.S. Pat. No. 4,851,406 discloses cardiotonic compounds of the following formula:
wherein: A is a five-membered, or six-membered ring heterocycle; X is a bond, an alkylene, or a vinylene radical; R1 is a H, alkyl, alkenyl, cycloalkyl, cycloalkenyl, carboxyl, cyano, alkylcarbonyl, alkoxycarbonyl, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl or aryl radical; R2 is H, alkyl, trihalogenomethyl, hydroxyl, cycloalkyl, cyano, carboxyl, cycloalkenyl, carboxyl, cyano, alkylcarbonyl, alkoxycarbonyl, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl or aryl radical; and R3 is a hydrogen atom.
WO 96/32379 teaches PDE-inhibitor compounds of the following formula I:
wherein R1 is a H, halogen, nitro, carboxy, protected carboxy, lower alkenyl, or acyl; R2 is H, halogen, carboxy, lower alkenyl, or acyl; R3 is a lower alkenyl, or lower alkenyl, both optionally substituted; and R4 is carboxy, protected carboxy, or acyl.
WO 9928297 relates to substituted indoles of the following formula with thrombin inhibiting effect and fibrinogen receptor antagonist effect.
where: Ra is halogen, carboxy, R3R4N—CO—, R3R4SO2—, or R4R5N—; Rb and Rd are either alkyl or R2-A where R2 is a phenyl optionally substituted and A is an alkylene or a substituted alkylene; and Rc is a hydrogen, or alkyl.
EP 0 655 439 teaches 5,6 fused ring bicyclic compounds inclusive of indoles, benzofurans, and benzothiophenes corresponding the following formula as platelet aggregation inhibitors.
